Media-defined optical logic circuitry design

ABSTRACT

A media-defined optical logic circuit composed of a set of light-transmitting polyhedral prisms arranged so that a pair of adjacent prisms can exchange photonic signals through adjacent surfaces. Each prism contains one or more quantum dots that, when excited by a photonic signal received from an adjacent prism, respond by emitting light that becomes an incoming photonic signal for an adjacent prism. Photonic signals are propagated through the circuit in this manner along light-guide paths created by shading certain surfaces to render them fully or partially opaque. The prisms and shading are arranged such that the circuit performs a certain logic function. When the circuit receives a set of photonic input signals representing a binary input value, the circuit responds by emitting a set of photonic output signals that represent a binary output value determined by performing the logic function upon the binary input value.

BACKGROUND

The present invention relates generally to optical computer processingand specifically to the design of a logic circuit from a set of shadedoptical prisms that each may contain one or more quantum dots.

Unlike conventional electrical circuits, which represent bits of data asvariations in voltage levels of an electrical signal, optical (or“photonic”) circuitry represents data as variations in light intensityof a photonic signal. Such light may be introduced to the circuit by anyknown means, such as by an external laser or a UV light sources.

Photonic circuits offer advantages over electrical circuits like aslower power consumption, less heat generation, and the theoretic abilityto achieve greater processing speeds and physically smaller circuits.These benefits may be especially important in newer classes of devicesthat require smaller, higher-performance, and more efficient processingcapabilities, such as quantum computers and next-generation mobile orembedded devices.

Current efforts to exploit the advantages of photonic computing aim tointegrate discrete optical circuits into electrical computer systems.This approach, however sacrifices some of the benefits of opticalprocessing. For example, a hybrid optoelectronic device may waste asignificant amount of power or reduce data-transmission speed every timeit must translate information-carrying signals between electrical andphotonic formats.

An all-optical computer processor would overcome many of these problems,but there is currently no way to efficiently manufacture optical logiccircuits in a manner capable of being scaled up to facilitatehigh-volume commercial manufacturing.

There is thus a need for a way to design and manufacture optical logicgates capable of being used as building blocks for more complex circuitslike optical computer processors.

SUMMARY

An embodiment of the present invention provides a media-defined opticallogic circuit capable of performing a logical operation, the circuitcomprising:

a set of polyhedral prisms physically arranged such that at least onesurface of each prism of the set of polyhedral prisms is adjacent to adistinct surface of another prism of the set of polyhedral prisms,

where a first prism of the set of polyhedral prisms comprises a firstembedded quantum dot of a set of quantum dots, a first prism-inputsurface, and a first prism-output surface, such that a sufficientlyenergetic first photonic signal received through the first prism-inputsurface is capable of exciting the quantum dot to produce light capableof being emitted through the first prism-output surface as a secondphotonic signal,

where the first prism-output surface is adjacent to a second prism-inputsurface of a second prism of the set of polyhedral prisms, such thatlight is capable of passing from the first prism to the second prismalong a path between the first prism-output surface and the secondprism-input surface,

where the logic circuit is configured to respond to a set of photoniccircuit-input signals, received from external light sources, by emittinga set of photonic circuit-output signals,

where the set of photonic circuit-output signals represents a binaryvalue derived by performing the logical operation upon a binary valuerepresented by the set of photonic circuit-input signals,

where the arrangement of the set of polyhedral prisms allows the circuitto receive the set of photonic circuit-input signals through inputsurfaces of one or more circuit-input prisms of the set of polyhedralprisms, and

where the arrangement of the set of polyhedral prisms allows the circuitto emit the set of circuit-output signals through circuit-outputsurfaces of one or more circuit-output prisms of the set of polyhedralprisms.

Another embodiment of the present invention provides a method of formingan optical logic circuit, the method comprising:

physically arranging a set of polyhedral prisms such that at least onesurface of each prism of the set of polyhedral prisms is adjacent to asurface of another prism of the set of polyhedral prisms,

where a first prism of the set of polyhedral prisms comprises a firstembedded quantum dot of a set of quantum dots, a first prism-inputsurface, and a first prism-output surface, such that a sufficientlyenergetic first photonic signal received through the first prism-inputsurface is capable of exciting the quantum dot to produce light capableof being emitted through the first prism-output surface as a secondphotonic signal, and

where the first prism-output surface is adjacent to a second prism-inputsurface of a second prism of the set of polyhedral prisms, such thatlight is capable of passing from the first prism to the second prismalong a path between the first prism-output surface and the secondprism-input surface; and

configuring the logic circuit to respond to a set of photoniccircuit-input signals, received from external light sources, by emittinga set of photonic circuit-output signals,

where the set of photonic circuit-output signals represents a binaryvalue derived by performing a logical operation upon a binary valuerepresented by the set of photonic circuit-input signals,

where the arrangement of the set of polyhedral prisms allows the circuitto receive the set of photonic circuit-input signals through inputsurfaces of one or more circuit-input prisms of the set of polyhedralprisms, and

where the arrangement of the set of polyhedral prisms allows the circuitto emit the set of circuit-output signals through circuit-outputsurfaces of one or more circuit-output prisms of the set of polyhedralprisms.

Yet another embodiment of the present invention provides a method ofusing an optical logic circuit, the method comprising:

submitting to the optical logic circuit, by means of external lightsources, a set of photonic circuit-input signals,

where the optical logic circuit comprises a set of polyhedral prismsphysically arranged such that at least one surface of each prism of theset of polyhedral prisms is adjacent to a surface of another prism ofthe set of polyhedral prisms,

where a first prism of the set of polyhedral prisms comprises a firstembedded quantum dot of a set of quantum dots, a first prism-inputsurface, and a first prism-output surface, such that a sufficientlyenergetic first photonic signal received through the first prism-inputsurface is capable of exciting the quantum dot to produce light capableof being emitted through the first prism-output surface as a secondphotonic signal, and

where the first prism-output surface is adjacent to a second prism-inputsurface of a second prism of the set of polyhedral prisms, such thatlight is capable of passing from the first prism to the second prismalong a path between the first prism-output surface and the secondprism-input surface,

where the logic circuit is configured to respond to the set of photoniccircuit-input signals by emitting a set of photonic circuit-outputsignals that represents a binary value derived by performing a logicaloperation upon a binary value represented by the set of photoniccircuit-input signals,

where the arrangement of the set of polyhedral prisms allows the circuitto receive the set of photonic circuit-input signals through inputsurfaces of one or more circuit-input prisms of the set of polyhedralprisms, and

where the arrangement of the set of polyhedral prisms allows the circuitto emit the set of circuit-output signals through circuit-outputsurfaces of one or more circuit-output prisms of the set of polyhedralprisms; and

reading the set of circuit-output signals emitted by the optical logiccircuit in response to receiving the photonic circuit-input signals.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the structure of a computer system and computer programcode that may be used to implement a method for designing media-definedoptical logic circuitry design in accordance with embodiments of thepresent invention.

FIG. 2 shows examples of prismatic crystals that be incorporated intoembodiments of the present invention.

FIG. 3 illustrates an optical NOT logic gate formed in accordance withembodiments of the present invention.

FIG. 4 illustrates an optical AND logic gate formed in accordance withembodiments of the present invention.

FIG. 5 illustrates an optical OR logic gate formed in accordance withembodiments of the present invention.

FIG. 6 illustrates an optical NAND logic gate formed in accordance withembodiments of the present invention.

FIG. 7A illustrates a first state of an optical NOR logic gate formed inaccordance with embodiments of the present invention.

FIG. 7B illustrates a second state of an optical NOR logic gate formedin accordance with embodiments of the present invention.

FIG. 8A illustrates a first state of an optical XOR logic gate formed inaccordance with embodiments of the present invention.

FIG. 8B illustrates a second state of an optical XOR logic gate formedin accordance with embodiments of the present invention.

FIG. 8C illustrates a third state of an optical XOR logic gate formed inaccordance with embodiments of the present invention.

FIG. 9 is a flow chart that illustrates the steps of a method formedia-defined optical circuitry design in accordance with embodiments ofthe present invention.

DETAILED DESCRIPTION

Embodiments of the present invention describe optical logic circuitryassembled from a set of polyhedral “crystals” or prisms that containquantum dots, and a method of manufacturing such a circuit.

As is known in the art, a quantum dot (also referred to in this documentas a “QD”) is a nanoscale “semiconductor” particle so small that itsoptical and electronic properties are subject to quantum mechanicaleffects.

Quantum dots emit light at certain frequencies in response to beingexcited by a sufficiently energetic electrical or photonic signal. It ispossible to control which frequencies of light may be emitted by aparticular QD by specifying the dot's size, shape, or material ofcomposition.

One or more quantum dots may, through means known in the art, beembedded into a polyhedral prism or crystal capable of passing light.The prism or crystal may be generated in a specific desired shape andwith a specific number of surfaces by controlling conditions under whichthe prism or crystal is created or grown. These conditions may includethe chemical composition of the prism or crystal or the temperature atwhich it is created. Examples of common polyhedral prism shapes areshown in FIG. 2.

Methods of embedding quantum dots into polyhedral light-passing prismsare known in the art and more are in development. These methods includehigh-temperature dual injection fabrication, which can produce variousdot sizes and chemical compositions and are sufficiently scalable toaccommodate large commercial applications that require hundreds of tonsof quantum dots.

Large volumes of QDs may also be produced by processes that synthesizetechnical continuous-flow systems by methods analogous to hot-injectiontechnologies, and by molecular-seeding methodologies that do not need ahigh-temperature injection step, but instead control particle size byseeding nanoparticle-growth sites of a molecular-cluster compound atmoderate temperatures. Other QD-fabrication technologies are based onsupercooled silicon CMOS semiconductors, on electromechanicaltechnologies that use templates to spawn self-assembling QD-basednanostructures, and on core-shell structures into which a region of onematerial in embedded into a second material.

Self-assembling quantum-dot structures may also be defined by arrays oflithographically patterned electrodes, or by a method of growing QDsknown in the art as Stranski-Krastanov growth. Genetically engineeredbiomanufacturing viruses and bacteria have also been used to generateinorganic nanocrystals capable of producing self-assembling quantum-dotnanostructures.

Embodiments of the present invention are flexible enough to accommodateany known or future method of gene quantum dots or of embedding QDs intoa crystal or non-crystalline polyhedral prism capable of receivingexternal light through one or more light-transmitting surfaces. When anexternal electrical or photonic stimulus of appropriate intensity,duration, or frequency reaches the embedded QD, the QD responds byemitting light at a specific frequency and intensity. The prism thenemits, through another surface, the light generated by the embedded QD.

One example of quantum-dot/crystal technology is described in pars.[0005]-[0011] and [0020]-[0029], and FIGS. 1-3, of the commonly-owned,co-pending United States Patent Application filed on Oct. 31, 2016, thecontents and disclosure of which is expressly incorporated by referenceherein in their entirety: U.S. patent application Ser. No. (15/339,902)for “OPTICAL STORAGE DEVICE UTILIZING QUANTUM SILOS.” This co-pendingapplication describes optical “silos” that store binary data by means ofquantum dots embedded into stacks of crystals.

Embodiments of the present invention extend this technology by shading(rendering opaque or semi-opaque) certain of a prism's surfaces. Thistechnique may be used to create a light-transmitting path, or waveguide,capable of routing light through the crystal between specific pairs ofshaded surfaces. By arranging prisms such that a photonic output of afirst prism becomes an input of a second, adjacent, prism, it is thuspossible to route information-carrying photonic signals through aspecific, deterministic path.

One or more surfaces of such a crystal may be completely shaded,preventing light from passing through the shaded surfaces, or may bepartially shaded to merely attenuate light passing through the partiallyshaded surfaces.

Such prismatic crystals may be organized into more complexnanostructures. In such structures, a light path between two crystalsmay be created by physically arranging the crystals so that lightemitted from a surface of one crystal can be received at a surface ofthe second crystal. In this manner, basic logic circuits, such as AND,OR, or XOR gates, may be constructed. These basic circuits may in turnbe combined, as would logic circuits based on any other type oftechnology, to form more complex circuits, or even entiremicroprocessors.

For example, a three-sided crystal with two 50%-shaded surfaces and oneunshaded surface may contain a QD capable of being excited by anexternal 100%-intensity photonic signal. Each of the shaded surfaces ispositioned to receive light output from another prism capable oftransmitting a 100%-intensity photonic signal. Because the semi-shadedsurfaces reduce the intensity of incoming light by 50%, the three-sidedcrystal will receive 100%-intensity photonic input only if both shadedsurfaces receive an external signal simultaneously. Therefore, theembedded QD will emit a 100%-intensity signal only if the three-sidedcrystal receives two 100%-intensity signals.

If a 100%-intensity photonic signal is deemed to represent a logical 1and 0% intensity deemed to represent a logical 0, the three-sidedcrystal thus performs a rudimentary logical AND function, producing anoutput =1 only when receiving two inputs both equal to 1.

Similarly, a completely unshaded three-sided crystal might theoreticallyimplement a rudimentary version of a logical OR function. In this case,a 100%-intensity photonic signal was received through either unshadedinput surface would be sufficient to excite the embedded QD to product a100%-intensity logical I output.

Embodiments of the present invention implement this inventive concept inorder to generate optical logic circuits where photonic signals aregenerated by quantum dots embedded into crystal prisms, and where theshape, geometry, number of surfaces, and shading of each prism, and thetwo-dimensional or three-dimensional organization of the prisms, definesbinary logic operations performed by the optical circuit.

The present invention may be a system a method, and/or a computerprogram product at any possible technical detail level of integration.The computer program product may include a computer readable storagemedium (or media) having computer readable program instructions thereonfor causing a processor to carry out aspects of the present invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, configuration data for integrated circuitry, oreither source code or object code written in any combination of one ormore programming languages, including an object oriented programminglanguage such as Smalltalk, C++, or the like, and procedural programminglanguages, such as the “C” programming language or similar programminglanguages. The computer readable program instructions may executeentirely on the user's computer, partly on the user's computer, as astand-alone software package, partly on the user's computer and partlyon a remote computer or entirely on the remote computer or server. Inthe latter scenario, the remote computer may be connected to the user'scomputer through any type of network, including a local area network(LAN) or a wide area network (WAN), or the connection may be made to anexternal computer (for example, through the Internet using an InternetService Provider). In some embodiments, electronic circuitry including,for example, programmable logic circuitry, field-programmable gatearrays (FPGA), or programmable logic arrays (PLA) may execute thecomputer readable program instructions by utilizing state information ofthe computer readable program instructions to personalize the electroniccircuitry, in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the blocks may occur out of theorder noted in the Figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

FIG. 1 shows a structure of a computer system and computer program codethat may be used to implement a method for media-defined optical logiccircuitry design in accordance with embodiments of the presentinvention. FIG. 1 refers to objects 101-117.

In FIG. 1, computer system 101 comprises a processor 103 coupled throughone or more I/O Interfaces 109 to one or more hardware data storagedevices 111 and one or more I/O devices 113 and 115.

Hardware data storage devices 111 may include, but are not limited to,magnetic tape drives, fixed or removable hard disks, optical discs,storage-equipped mobile devices, and solid-state random-access orread-only storage devices. 1/0 devices may comprise, but are not limitedto: input devices 113, such as keyboards, scanners, handheldtelecommunications devices, touch-sensitive displays, tablets, biometricreaders, joysticks, trackballs, or computer mice; and output devices115, which may comprise, but are not limited to printers, plotters,tablets, mobile telephones, displays, or sound-producing devices.

In embodiments of the present invention two or more of the outputdevices 115 may be lasers 117. These lasers 117 may be used to operate,fabricate, or test the optical logic circuits shown in FIGS. 3-8C.

Data storage devices 111, input devices 113, and output devices 115 maybe located either locally or at remote sites from which they areconnected to I/O Interface 109 through a network interface.

Processor 103 may also be connected to one or more memory devices 105,which may include, but are not limited to, Dynamic RAM (DRAM), StaticRAM (SRAM), Programmable Read-Only Memory (PROM), Field-ProgrammableGate Arrays (FPGA), Secure Digital memory cards, SIM cards, or othertypes of memory devices.

At least one memory device 105 contains stored computer program code107, which is a computer program that comprises computer-executableinstructions. The stored computer program code includes a program thatimplements a method for media-defined optical logic circuitry design inaccordance with embodiments of the present invention, and may implementother embodiments described in this specification, including the methodsillustrate in FIGS. 1-9. The data storage devices 111 may store thecomputer program code 107. Computer program code 107 stored in thestorage devices 111 is configured to be executed by processor 103 viathe memory devices 105. Processor 103 executes the stored computerprogram code 107.

In some embodiments, rather than being stored and accessed from a harddrive, optical disc or other writeable, rewriteable, or removablehardware data-storage device 111, stored computer program code 107 maybe stored on a static, nonremovable, read-only storage medium such as aRead-Only Memory (ROM) device 105, or may be accessed by processor 103directly from such a static, nonremovable, read-only medium 105.Similarly, in some embodiments, stored computer program code 107 may bestored as computer-readable firmware 105, or may be accessed byprocessor 103 directly from such firmware 105, rather than from a moredynamic or removable hardware data-storage device 111, such as a harddrive or optical disc.

Thus the present invention discloses a process for supporting computerinfrastructure, integrating, hosting, maintaining, and deployingcomputer-readable code into the computer system 101, wherein the code incombination with the computer system 101 is capable of performing amethod for media-defined optical logic circuitry design.

Any of the components of the present invention could be created,integrated, hosted, maintained, deployed, managed, serviced, supported,etc. by a service provider who offers to facilitate a method formedia-defined optical logic circuitry design. Thus the present inventiondiscloses a process for deploying or integrating computinginfrastructure, comprising integrating computer-readable code into thecomputer system 101, wherein the code in combination with the computersystem 101 is capable of performing a method for media-defined opticallogic circuitry design.

One or more data storage units 111 (or one or more additional memorydevices not shown in FIG. 1) may be used as a computer-readable hardwarestorage device having a computer-readable program embodied thereinand/or having other data stored therein, wherein the computer-readableprogram comprises stored computer program code 107. Generally, acomputer program product (or, alternatively, an article of manufacture)of computer system 101 may comprise the computer-readable hardwarestorage device.

While it is understood that program code 107 for a method formedia-defined optical logic circuitry design may be deployed by manuallyloading the program code 107 directly into client, server, and proxycomputers (not shown) by loading the program code 107 into acomputer-readable storage medium (e.g., computer data storage device111), program code 107 may also be automatically or semi-automaticallydeployed into computer system 101 by sending program code 107 to acentral server (e.g., computer system 101) or to a group of centralservers. Program code 107 may then he downloaded into client computers(not shown) that will execute program code 107.

Alternatively, program code 107 may be sent directly to the clientcomputer via e-mail. Program code 107 may then either be detached to adirectory on the client computer or loaded into a directory on theclient computer by an e-mail option that selects a program that detachesprogram code 107 into the directory.

Another alternative is to send program code 107 directly to a directoryon the client computer hard drive. If proxy servers are configured, theprocess selects the proxy server code, determines on which computers toplace the proxy servers' code, transmits the proxy server code, and theninstalls the proxy server code on the proxy computer. Program code 107is then transmitted to the proxy server and stored on the proxy server.

In one embodiment, program code 107 for a method for media-definedoptical logic circuitry design is integrated into a client, server andnetwork environment by providing for program code 107 to coexist withsoftware applications (not shown), operating systems (not shown) andnetwork operating systems software (not shown) and then installingprogram code 107 on the clients and servers in the environment whereprogram code 107 will function.

The first step of the aforementioned integration of code included inprogram code 107 is to identify any software on the clients and servers,including the network operating system (not shown), where program code107 will be deployed that are required by program code 107 or that workin conjunction with program code 107. This identified software includesthe network operating system, where the network operating systemcomprises software that enhances a basic operating system by addingnetworking features. Next, the software applications and version numbersare identified and compared to a list of software applications andcorrect version numbers that have been tested to work with program code107. A software application that is missing or that does not match acorrect version number is upgraded to the correct version.

A program instruction that passes parameters from program code 107 to asoftware application is checked to ensure that the instruction'sparameter list matches a parameter first required by the program code107. Conversely, a parameter passed by the software application toprogram code 107 is checked to ensure that the parameter matches aparametered by program code 107. The client and server operatingsystems, including the network operating systems, are identified andcompared to a list of operating systems, version numbers, and networksoftware programs that have been tested to work with program code 107.An operating system, version number, or network software program thatdoes not match an entry of the list of tested operating systems andversion numbers is upgraded to the listed level on the client computersand upgraded to the listed level on the server computers.

After ensuring that the software, where program code 107 is to bedeployed, is at a correct version level that has been tested to workwith program code 107, the integration is completed by installingprogram code 107 on the clients and servers.

Embodiments of the present invention may be implemented as a methodperformed by a processor of a computer system, as a computer programproduct, as a computer system, or as a processor-performed process orservice for supporting computer infrastructure.

FIG. 2 shows examples of prismatic crystals that may be incorporatedinto embodiments of the present invention. FIG. 2 shows elementsidentified by reference numbers 201-211 a.

Each of the examples shown in FIG. 2 shows one view of a commonly shapedprism that may be used to implement optical logic circuits in compliancewith embodiments of the present invention. These prisms 201, 203, 205,207, 209, and 211 may be designed and created by any means known in theart, such as through methods of crystallography by which a crystal maybe grown into a specific size and shape as a function of the crystal'selemental or chemical composition.

These prisms 201, 203, 205, 207, 209, and 211 each comprise at least onequantum dot 201 a, 203 a, 205 a, 207 a, 209 a, or 211 a (or “QD”)embedded into a prism through means known in the art.

Elements 201 and 203, for example, show two views of a 26-sided“corner-cut cube” crystal shape, viewed, respectively from a top viewand a side view. Elements 205 and 207 show, respectively, a sidecenter-cut view and a top view of a 30-sided “corner receiver” crystalshape. Elements 209 and 211 show, respectively, top and corner views ofa 14-sided “central crystal” shape.

As described above, each surface of these crystals may be left unshaded(rendering it always capable of transmitting light), may be partiallyshaded (allowing the surface to pass only a portion of a light signal,or completely shaded (rendering the surface opaque).

The QD quantum dot encased in each of these crystals is capable of beingexcited by an external light source, such as a laser, if the crystal'ssurface shading creates a path through which the external source mayreach the QD. When excited, the QD may emit light of a specificintensity and frequency, which may then be emitted from an unshadedsurface of the crystalline prism. In other words, the prism, whenproperly shaded, may act as a waveguide.

The examples of FIG. 2 should not be construed to limit embodiments ofthe present invention to the prismatic shapes shown. Embodiments of thepresent invention are flexible enough to accommodate any shape prismcapable of being created and deemed necessary by an implementer in orderto implement a specific desired logical operation

FIG. 3 illustrates an optical NOT logic gate formed in accordance withembodiments of the present invention. FIG. 3 comprises elements 301-315.

FIG. 3 shows a simple embodiment of the present invention thatimplements a media-defined optical processor designed to perform alogical NOT or inversion operation. Although not comprising prisms orquantum dots, this example is included here to provide context for themore complex implementations of FIGS. 4-8C.

Items 301 and 303 represent switchable external sources of light.Embodiments and examples described in this document refer to thesesources as “lasers,” but other embodiments may comprise any type oflight sources known in the art. By convention, these external sources oflight will be represented as a white arrow to indicate a source that isfully switched ON, and as a black arrow to indicate a light source thatis switched OFF.

In embodiments that implement binary logic circuits, these ON and OFFstates may indicate a laser that is either emitting light at full power(100%) or is not emitting any light (0%). But in some implementations,more than two states may be possible, or ON and OFF states may berepresented by other light levels. Some implementations may, forexample, comprise quantum dots capable of responding to light levelslower than 100%, allowing power savings by using external light sourcesat intensities less than 100%. In circuits that implement negativelogic, a ON state may be indicated by a lower light intensity than wouldbe an OFF state.

In FIG. 3, black-arrow item 301 thus represents a first input lightsource A that is currently in an OFF or 0 state. Similarly, white-arrowitem 303 represents a second input light source B that is currently inan ON or 1 state.

External light source 301 controls a laser 305 by means of alight-activated switch 309. In FIG. 2, switch 309 is shown as aconventional SPST switch or relay, but in other embodiments, other typesof switches and more complexing topologies may be used. Embodiments ofthe present invention may comprise light-activated switches known in theart (such as liquid-crystal light valve (LCLV) switches) that are openedby an activating light signal, or may comprise light-activated switchesthat are closed by an activating light signal. In the example of FIG. 2,switches 309 and 311 are by default closed (thus switching on acorresponding laser 305 or 307), but may be opened by a higher-intensitylight source.

This dual light-source arrangement is a most general case, in whichlight source 301 may be an incoming logical bit stream. As mentionedabove, this external source 301 may be a laser triggered by an externalcondition or it may be any other type of light source capable oftriggering light-activated switch 309. Similarly, laser 305 may be alaser, but it may also be any other type of light source capable ofproducing energy of a type capable of exciting a quantum dot embeddedinto a prism.

In a simple implementation, this mechanism may be collapsed into asingle switchable light-source. In such cases, light source 301 might,for example, comprise a switchable laser that is controlled by externalconditions, such as a user control, a manual switch, output receivedfrom another electrical or photonic circuit, or a laboratory conditionthat is extrinsic to the present invention. However, examples andembodiments described in this document will, for illustrative purposes,describe the more general mechanism shown here.

Light source 305 emits light 313 when laser 305 is switched on.Similarly, external light source 303 controls light-activated switch311, which in turn switches laser 307 on or off. When switched on, laser307 emits light 315.

This mechanism may implement logic tables for a pair of conventional NOTgates:

TABLE 1A A Y 0 1 1 0

TABLE 1B B Y 0 1 1 0

In FIG. 2, input A 301 is shown to be in an OFF or 0 state.Light-activated switch 309, which, in these examples, assumes an opencondition when detecting an external light source is in its defaultclosed state because input A 301 is 0. The closed switch allows laser305 to emit high-energy light 313, producing an ON or 1 condition 313.

Similarly, input B 303 is shown to be in an ON or 1 state. This signalopens light-activated switch 311, which interrupts light emitted bylaser 307 (or diverts or turns off laser 307), producing an OFF or 0condition 315.

FIG. 4 illustrates an optical AND logic gate formed in accordance withembodiments of the present invention. FIG. 4 comprises elements 401-415.

The optical circuit shown in FIG. 4 is a two-input AND gate. As in FIG.3, inputs A 401 and B 402 are external light sources, similar to thoseidentified by items 301, 303, 313, or 315 in FIG. 3.

Item 400 is an optical circuit that implements the AND logic by means ofthree shaded prisms 407, 409, and 411, each of which comprises a quantumdot capable of being excited by a light signal of sufficient intensityor frequency. Each surface of these prisms may be fully or partiallyshaded in order to create conditional waveguides capable of directinglight between the prisms.

Prismatic optical circuit 405 has two inputs A and B that equate,respectively, to the unshaded top surfaces of prism 407 and 409. Circuit400's output Y is emitted from the bottom surface of prism 411. Otherexamples in FIGS. 5-8C will use similar conventions to indicate inputand output surfaces of prism-based optical circuits.

The surfaces between prisms 407 and 409 are, for example, 100% shaded byshading 413. This prevents light being transferred between prism 407 andprism 409. For example, light that has entered prism 407 from anexternal source, or that has been generated by a quantum dot embeddedinto prism 407 cannot enter prism 409 or excite the quantum dot embeddedinto prism 409. This 100% shading creates an unconditional waveguidethat prevents input signals 401 and 403 from being mixed at the input tothe optical circuit 400.

TABLE 2 A B Y 0 0 0 0 1 0 1 0 0 1 0 1

In the example of FIG. 4, input A 401 is 0 (indicated by the incomingblack arrow) and input B 403 is 1 (indicated by the white arrow). InputA enters the optical circuit 405 through the upper surface of prism 407,and input B enters through the upper surface of prism 409. 100% shading413 prevents these optical inputs from bleeding between prisms 407 and409. The output of the logical circuit 405 is emitted from the bottomsurface of prism 411.

Prism 411 is partially isolated from prisms 407 and 409 by 50% shading417 and 415. If the quantum dot embedded in prism 411 can only beexcited by a light level equal to a 100% laser output, then light guidedinto prism 411 from only prism 407 or from only prism 409 isinsufficient to excite the QD, and thus insufficient to output a 1signal from the bottom surface of prism 411.

FIG. 4 shows a logic state similar to the second row of Table 2, withinput A 401=0 and input B 403=1. As can be seen in the figure, the 0%intensity level of input A 401 fails to excite the quantum dot embeddedin prism 407, resulting in no light passing through the shaded surface417 of prism 411. The 100% intensity level of input B 401 does, however,excite the quantum dot embedded in prism 407, resulting in a 50% lightlevel passing through the 50% shaded surface 417 of prism 411. 50%intensity, however, is insufficient to excite the QD embedded in prism411, resulting in a 0 output.

Although not shown in the figure, if both input A 401 and input B 403were set equal to 1, optical circuit 405 would emit a 100% light level,producing a logical 1 output.

In this case, the two 100% inputs would each excite one of the QDsembedded into prisms 407 and 409. These excitations would each emit a100% light signal, each of which is attenuated by shading 415 or 417such that two 50%-intensity signals enter prism 411. These two signalsadd up to a 100% signal, sufficient enough to excite the QD embedded inprism 411. That excited QD emits a 100%-intensity light signal, which isemitted from the output of circuit 405 through the bottom surface ofprism 411, as a logical 1 signal.

FIG. 5 illustrates an optical OR logic gate formed in accordance withembodiments of the present invention. FIG. 5 comprises elements 500-511.

Here, optical OR circuit 500 comprises three prisms 507, 509, and 511,each of which contains an embedded QD capable of emitting a light signalof a particular frequency and intensity when excited by an externallight source. As in previous figures, the circuit 500 receives anoptical input signals A 501 and B 503 respectively through the unshadedupper surfaces of prisms 507 and 509 and emits an optical output signalthrough the unshaded bottom surface of prism 511. As in FIG. 4, thecommon surfaces shared by prisms 507 and 509 are shaded 100%, preventinginput signals from bleeding between prisms 507 and 509. There is notshading between output prism 511 and either input prism 507 or 509.

TABLE 3 A B Y 0 0 0 0 1 1 1 0 1 1 1 1

FIG. 5 illustrates the second logic state listed in the OR logicillustrated by Table 3. Here, input A 501 assumes a 0 state, which failsto excite the QD embedded in prism 507. Thus no light is transmittedfrom prism 507 to output prism 511 input B 503, however assumes a 1state, which does excite the QD embedded in prism 507, causing the QD toemit a 100%-intensity light signal that passes through the unshadedadjacent surfaces of prisms 509 and 511. Thus a 100% light signal istransmitted from prism 507 to output prism 511, resulting in an outputstate of Y=1. Similar results would occur if input A 501 was set to 1and input B 503 was set to 0.

If both inputs A 501 and B 503 are set 1, then two 100% light signalspass from prisms 507 and 509 to output prism 511. That aggregated lightlevel is sufficient to excite the QD embedded into prism 511, thusproducing an output signal Y=1. Conversely, if both inputs A 501 and B503 are set to 0, then no light enters prisms 507 or 509, the QDsembedded in prisms 507 and 509 are not excited to produce light, and nolight is transmitted to output prism 511. Thus output prism 511 producesno output, resulting in an output signal Y=0.

FIG. 6 illustrates an optical NAND logic gate formed in accordance withembodiments of the present invention. FIG. 6 comprises elements 600-623.

FIG. 6 shows an embodiment that combines the input-switching function ofFIG. 3 with the prism-based optical circuitry 600 similar to that of theoptical OR gate of FIG. 5. The resulting circuitry implements the NANDlogic shown in Table 4. Another way to think about the implementation ofFIG. 6 is as a combination of the NOT gate of FIG. 3 with the OR gate ofFIG. 5. As is known in the field of binary logic, inverting an ORfunction produces a NAND function, so in FIG. 6, sequentially combiningoptical NOT and OR functions correctly produces an expected NAND output.As with other binary logic technologies, embodiments of the presentinvention may similarly be scaled up to produce enormously complex logicfunctions in a similar manner, by combining more primitive logicfunctions.

TABLE 4 A B Y 0 0 1 0 1 1 1 0 1 1 1 0

FIG. 6 illustrates one state of the NAND logic shown in Table 4. Here,an input signal A 601 is set to 1, or 100% light intensity, and inputsignal B 603 is set to 0, or 0% light intensity. As discussed in FIG. 3,the 1 input 601 activates switch 609 to interrupt laser 605. Thus a0%-intensity logical 0 signal 613 is received by the upper surface ofprism 619.

Similarly, the 0 input 603 leaves switch 611 in its default closedstate, thus allowing laser 607 to transmit a 100%-intensity signal 615to the upper surface of prism 621. As described in previous figures,common surfaces of prisms 619 and 621 are shaded 100% to preventincoming light from bleeding between prisms 619 and 621.

In this example, prism 619's QD is not excited, so no light istransmitted through the unshaded prism surface common to prisms 619 and623. However, prism 621's QD is excited by laser 607's output 615, thusemitting light that passes through unshaded surfaces into output prism623. This 100% light is sufficient to excite the QD embedded in prism623, resulting in a logical 1 output signal being emitted from thebottom surface of output prism 623.

Other states defined by NAND logic Table 4 are implemented in a similarway by the circuitry of FIG. 6.

FIG. 7A illustrates a first state of an optical NOR logic gate formed inaccordance with embodiments of the present invention. FIG. 7A compriseselements 700-727.

As in FIG. 6, FIG. 7A builds a logic function by cascading a sequence ofprimitives. As is known in the art, a NOR function may be decomposedinto a NOT function and an AND function. Accordingly, FIG. 7a implementsa NOR function as a sequence of a NOT light-switching function (similarto that of FIG. 3) with an AND gate 700, as implemented in FIG. 4, item400. Table 5 tabulates the logic states of a NOR gate.

TABLE 5 A B Y 0 0 1 0 1 0 1 0 0 1 0 0

The upper part of FIG. 7A, comprising items 701-715, are identical inform and function to analogous elements of FIG. 3. Inputs A 701 and B703 comprise light signals capable of switching light-activated switches707 and 709, which permit or interrupt light signals 713 and 715 fromlasers 705 and 707. Because of the configuration of switches 709 and711, outputs 713 and 715 of this mechanism are inversions of the statesof each input signal 701 and 703. Items 701-715 thus act as an inverteror NOT gate.

Optical AND circuit 700 comprises elements 717-727, which are identicalin form and function to analogous elements of FIG. 4.

As in previous examples, input prisms 719 and 721 are isolated from eachother by 100% shading applied to their common surfaces. Similarly, as inFIG. 4, 50% shading 725 and 727 is applied to common surfaces betweenprisms 719 and 723, and to the common surfaces between prisms 721 and723. This 50% shading is capable of decreasing the intensity of lightpassing through those surfaces by 50%.

As is the case throughout embodiments and examples described in thisdocument, this shading may be applied by any means known in the art,including etching, chemical treatment, dying, doping, or coating.Shading may be achieved by applying an opaque, translucent, refractive,reflective, or other type of coating known in the art and capable oflimiting light transmission.

The example of FIG. 7A illustrates the second logic state enumerated inTable 5, where input A 701=1 (a 100% light-intensity level) and input B703=0 (a 0% light-intensity level). The mechanism of elements 705-711inverts these signals, producing a 0% light signal 713, which istransmitted to prism 719 through the unshaded upper surface of prism719, and a 100%-intensity signal 715 that is transmitted to prism 721through the unshaded upper surface of prism 721.

As a result, the QD of prism 719 is not excited and the QD of prism 721is excited, producing a 100%-intensity light signal, which is attenuatedto 50% intensity by shading 727. Output prism 723 thus receives only a50%-intensity signal, which is less than the 100% intensity required toexcite the QD embedded in prism 723. Circuit 700 thus produces nooutput, resulting in an output state Y=0.

The optical circuitry of FIG. 7A uses similar means to generate correctNOR output states when responding to other combinations of input statesenumerated in Table 5. Another example of this procedure is described inFIG. 7B.

FIG. 7B illustrates a second state of an optical NOR logic gate formedin accordance with embodiments of the present invention. FIG. 7Bcomprises elements 700-727 and 751-757.

Items 700-727 are identical in form and function to analogously labeleditems in FIG. 7A. FIG. 7B elaborates on the example of FIG. 7A byillustrating how the circuitry of FIG. 7A and 7B conforms correctly toanother logic state of a NOR function, which is the first state listedin Table 5.

-   -   0 NOR 0=1

In FIG. 7A, input A 751 and input B 753 are both set to 0, whichcorresponds to 0%-intensity light signals. These 0 signals do not openlight-activated switches 709 and 711, allowing lasers 705 and 707 totransmit 100%-intensity logical 1 outputs 755 and 757 to prisms 719 and721. These light signals pass unimpeded through the unshaded uppersurfaces of prisms 719 and 721.

The QDs embedded in prisms 719 and 721 are each respectively excited bylight sources 755 and 757. Prisms 719 and 721 thus emit 100%-intensitysignals. These signals are each attenuated by 50% by the 50% shaders 725and 727 that shade light passing between prism 723 and either prism 719or 721.

Prism 723 thus receives two 50%-intensity signals that together havesufficient intensity to excite the QD of prism 723. A 100%-intensityoutput is thus emitted from the lower surface of prism 723 as outputY=1.

FIG. 8A illustrates a first state of an optical XOR logic gate formed inaccordance with embodiments of the present invention. FIG. 8A compriseselements 801 a-845, 8000-1, and 8000-2.

The optical logic gate shown in this figure consists of three componentsthat together implement the XOR logic enumerated in Table 6. In thisexample, these components are divided into two layers in order to betterillustrate their operation. In other embodiments, an optical circuitcreated by means of the present invention may comprise many such layersof components.

FIG. 8A comprises:

i) a NOT inverter module 805-811 identical in form and operation to theNOT circuitry of FIG. 3;

ii) a more complex “Layer 1” optical-logic module 8000-1 that augmentsthe pentagonal cross-section prisms shown in the preceding examples,with prisms 823-827 that each have a six-sided cross-section;

iii) and a “Layer 1” OR module 8000-2 similar in form and function tothe OR circuitry of FIG. 5.

Embodiments of the present invention are flexible enough to accommodateany sort of organization or logical partitioning of optical circuits. Inthe example of FIGS. 8A-8C, we organize components such that a Level 1circuit has outputs and inputs that represent inputs and outputs of anoverall logic table. Level 2 circuits perform subordinate functionsrequired by the Level 1 circuit to produce output. Similarly,deeper-level circuits would each perform such a function for anext-higher level. This choice of organization methodology is selectedfor pedagogical purposes and should not be construed to be an essentialelement of the present invention.

As mentioned earlier, embodiments of the present invention may compriseprisms that have any sort of shape and have any number of sides that arecapable of being manufactured by processes known in the art. Shape,size, and surface configurations may be required in some implementationsin order to physically fit prisms together in a manner that enablesdesired light guides to be created. Certain shapes may, for example, berequired when implementing functions that require a prism to have alarger number of input surfaces.

Similarly, embodiments may comprise prisms that have different degreesof shading than are described in the examples and embodiments of thefigures. Consider, for example, a prism that is intended to produceoutput only when receiving three simultaneous 100%-intensity signals. Ifthe prism's CSD can only be excited by a 100%-intensity signal, thethree-way logic requirement may be met by applying 67% shading to eachof three surfaces of the prism that are adjacent to prisms capable ofemitting a 100%-intensity signal. Those shadings reduce each incomingsignal to 33%-intensity, thus preventing the prism from receiving100%-intensity light unless three incoming signals reach the prism'sinput surfaces.

In the circuitry of FIG. 8A, inputs A and B each have two entry points.Input A 801 a is received both at the unshaded upper surface of prism835 and at light-activated switch 809. Similarly, input B 803 a isreceived both at the unshaded upper surface of prism 837 and atlight-activated switch 811. In FIG. 8A, both inputs 801 a and 803 a arein a logical 0 state, with 0% intensity.

TABLE 6 A B Y 0 0 0 0 1 1 1 0 1 1 0 0

As in the NOT circuitry of FIG. 3, light-activated switches 809 and 811are toggled by inputs A 801 a and B 803 a to control the emission of100%-intensity light from lasers 805 and 807. Here, the two 0-levelinput signals result in two 100%-intensity laser beams being transmittedto prisms 819 and 821.

Prisms 819 and 821 are isolated from each other by 100% shading 817 inorder to prevent light from bleeding between the two prisms. Similarly,prisms 835 and 837 are isolated from each other by 100% shading 845, andprism 827 is isolated by 100% shading 843 from prisms 823 and 825.Finally, prism 829 is partially isolated from prisms 825 and 827 by 50%shadings 831 and 833. Similar patterns of shading may be selected, asdesired by an implementer, in order to create unconditional orconditional waveguides that route signals through the logic circuitry ina desired manner.

In the example of FIG. 8A, the QDs embedded into prisms 819 and 821 areboth excited by 100% input signals 813 a and 815 a and each thus emit alight signal. These signals are transmitted to prism 823 throughunshaded surfaces, and prism 823 in turn generates and transmits a 100%light signal to prism 825.

Inputs A 801 a and B 803 a are also fed directly into the upper “input”surfaces of prisms 835 and 837. Neither of these inputs (both at 0%intensity) is capable of exciting any of the quantum dots in the Level 2module 8000-2.

Output prism 839 of Level 2 module 8000-2 transmits a light signal 841 ato an input surface on prism 827 of Level 1 module 8000-1. The 0% signal841 a is insufficient to excite the quantum dot embedded into prism 827.

Level 1 output prism 829 implements AND-gate logic, much like theoptical circuitry shown in FIG. 4, Prism 829 thus produces a logical 1(100% intensity) signal only when both prisms 825 and 327 transmitsimilar logical 1 signals to prism 829 through the 50% shaders 831 and833.

Here, prism 825 transmits a 1 signal to prism 829, but prism 827, havingreceived a 0 signal from Level 2 module 8000-2, transmits a 0 signal toprism 829. Prism 829, therefore receives only a 50%-intensity input,insufficient to excite the CSD embedded within prism 829. The XOR logicof FIG. 8A therefore correctly produces a 0 output Y through the bottomsurface of output prism 829.

FIGS. 8B and 8C explain how the optical logic of FIG. 8A correctlyproduces other logic states enumerated in Table 6.

FIG. 8B illustrates a second state of an optical XOR logic gate formedin accordance with embodiments of the present invention. FIG. 8Bcomprises elements 801 b-845, 8000-1, and 8000-2.

Elements 805-811, 817-833, 835-839, 843-845, 8000-1, and 8000-2 areidentical in form and function to similarly numbered items in FIG. 8A.In this example, however Input A 801 b is a 100%-intensity logical 1light signal and Input B 803 b is a 0%-intensity

As described in previous examples, these inputs result in thetransmission of a 100%-intensity light signal 813 b to prism 819 and thetransmission of a 0%-intensity light signal 815 b to prism 821. The QDembedded in prism 819 responds by sending a 100%-intensity signal toprism 823, which then forward the signal to prism 825.

At Level 2 8000-2, signal A 8011) and signal B 803 b cause prism 839 totransmit a 100% signal to an unshaded input surface of prism 827 onLevel 1 8000-1. Because QDs embedded with both prism 825 and prism 827are excited, the two resulting 100%-intensity signals, even whenattenuated by 50% shadings 831 and 833, are sufficient to excite the QDcomprised by output prism 829.

Prism 829 thus correctly produces a 100%-intensity output Y=1.

If the states of input A 801 b and B 803 b were reversed, the opticalcircuitry of FIG. 8B would produce a similar output. This may be seen bynoting the symmetry with respect to the two inputs that exists in allthree components of FIGS. 8A-8C.

FIG. 8C illustrates a third state of an optical XOR logic gate formed inaccordance with embodiments of the present invention. FIG. 8 compriseselements 801 c-845, 8000-1, and 8000-2.

Elements 805-811, 817-833, 835-839, 843-845, 8000-1, and 8000-2 areidentical in form and function to similarly numbered items in FIGS. 8Aand 8B. In this example, both Input A 801 c and Input B 803 c are100%-intensity signals equal to a logical value of 1.

By means described in previous examples, these inputs result in thetransmission of a 0%-intensity light signals 813 c and 815 c to prisms819 and 821 of Level 1 circuitry 8000-1. These 0%-intensity inputs failto excite any quantum dots along the wave guide comptising prisms819-825.

At Level 2 8000-2, signal A 801 c and signal B 803 c excite quantum dotsin prisms 835 and 837, in turn exciting prism 839. Level 1secondary-input Prism 827 thus receives a 100%-intensity signal 841 cfrom Level 2's output prism 839.

Because the CSD embedded in prism 825 has not been excited, only prism827 transmits 100%-intensity light to output prism 829. Because thislight is attenuated by 50% shading 833, the resulting 50%-intensitylight is insufficient to excite the prism 829 quantum dot. Prism 829thus correctly produces a 0%-intensity photonic output Y=0.

FIG. 9 is a flow chart that illustrates the steps of a method formedia-defined optical logic circuitry design in accordance withembodiments of the present invention. FIG. 9 comprises steps 900-950.

In step 900, processor 103 of a computerized optical-logic design systemreceives one or more binary logic tables (or other known type ofrepresentation) of a set of binary-logic operations to be implemented asan optical logic circuit.

In step 910, the processor 103 decomposes the desired binary-logicoperation into one or more sequences of simpler logical functions. Thesesimpler circuits may comprise primitive binary logic functions likebinary NOT, AND, OR, XOR, NAND, or NOR gates. In other embodiments, thesimpler logical functions may comprise less-primitive functions, such asshift registers, that may be assembled from binary logic gates.

This step may be performed through any methods known in the art of logicdesign, and may be performed through completely automated means, inwhich processor 103 automatically designs low-level logic necessary toimplement the desired binary-logic operations identified in step 900. Inother embodiments, all or part of this step may be performed manuallythrough known logic-design procedures, or by specialized softwaresystems configured to design binary logic. In all cases, the designprocedures implemented in this step may be similar to known methods oflogic design applicable to circuits implemented through any sort ofunderlying technology or medium.

In step 920, the processor 103 translates the logical elementsdecomposed in step 910 into a set of optical circuits that each compriseone or more polyhedral prisms into which have been embedded quantumdots.

As described in FIGS. 3-8C, each prism may comprise one or morelight-transmissive surfaces that each act as either an input or anoutput to the prism. One or more external input light signals may enterthe prism through such an input surface and an output signal generatedby an excited embedded QD may exit the prism as an output signal throughone or more of the output surfaces.

Each surface of such a prism may be completely or partially shaded inorder to prevent or attenuate external photonic signal, similar to theway that an electrical signal of an electronic circuit may be attenuatedor completely blocked by non-conductive or semi-conductive materials.

Many methods of shading surfaces are known in the art of molecularcrystallography and in other fields related to, nanotech manufacturing.It is possible, for example, to selectively apply coatings or to alterthe molecular makeup of specific surfaces in order to darken thosesurfaces or to give them reflective properties. In some cases, a shadedsurface may be configured to be electrically or optically rewritable,allowing software-defined circuit upgrades to be applied to a circuitafter-the-fact.

As explained in the examples of FIGS. 3-8C, shaded prism surfaces ofsuch logical circuits can be organized into light guides that routephotonic signals through a set of prisms in configurations implementdesired logic operations.

These prisms may be physically arranged into two-dimensional orthree-dimensional structures such that an input surface of a first prismis positioned to receive a photonic signal emitted by an output surfaceof a second prism. In some embodiments, such a structure may compriseinterconnected layers of two-dimensional “films” or “sheets,” analogousto layers in an electrical integrated circuit. However, given thecurrent state of the art of nanoscale-fabrication technologies, there isno requirement for such a limitation. And as such technologies continueto improve, increasingly complex three-dimensional structures willcontinue to become cost-effective.

A photonic logic circuit designed by the method of FIG. 9 may have anoverall set of exterior input surfaces capable of receiving a set ofinput signals and an overall set of exterior output surfaces capable ofemitting one or more output signals. If a row of the logic tablereceived in step 900 identifies a pair of corresponding input and outputstates, the circuit will emit a set of photonic signals from the outputsurfaces that represent an output state produced in response toreceiving, at the input surfaces, photonic inputs that represent thecorresponding input state.

The processor may determine the arrangement of the prisms in any wayknown in the art of logic design, including methodologies analogous tothose used when designing electrical logic circuits by assembling setsof logic gates.

For example, an electrical NAND function may be implemented inelectrical CMOS or TTL circuitry as by routing outputs of one or moreinverting NOT gates to the inputs of an OR gate (or vice-versa).Although embodiments of the present invention implement logic by meansof a fundamentally different technology, they nonetheless allow aphotonic NAND function to be designed, at a logical level, by similarlycascading logical NOT and OR functions. One example of this isillustrated in FIG. 6.

As illustrated by the examples of FIGS. 3-8C, embodiments of the presentinvention may implement basic logic gates by arranging specificallyshaped prisms in exemplary configurations shown in the figures. Butother arrangements of prisms are likewise capable of implementing thesame basic functions, including arrangements that comprise prisms withdifferent numbers of surfaces or different physical shapes, or that havedifferent patterns of shading.

Embodiments of the present invention are flexible enough to accommodateany sort of variation of or alternative to the examples shown in thefigures that is desired by an implementer or that is deemed to be moreefficient, cost-effective, easier to manufacture, compatible withextrinsic systems, or otherwise preferable to the sample gate structuresshown in the figures. Such logic-design choices may be selected by ahuman circuit designer or by computerized design software, using anymethodology analogous to known methods of logic design.

At the conclusion of step 930, the processor will have selected one ormore sets of prisms and determined how to arrange and shade those prismsin order to implement logic identified in step 900.

As described above, this task may be performed by straightforwardlyimplementing each logic gate identified in step 910 as an independentstructure similar to those illustrated in FIGS. 3-8C, and thenassembling those structures in a sequence defined by the logicalstructure identified in step 910. But many other structures are capableof performing the same logical functions, and embodiments of the presentinvention may accommodate any such structure that is desired by animplementer.

In step 930, the prisms, quantum dots, and shading specified in step 920are generated. This step may be performed by any means known in the art,including those described above in the opening to the DETAILEDDESCRIPTION section.

In step 940, the elements created in step 930 are organized intostructures specified in step 920. In some embodiments, steps 930 and 940may be combined into a single step that generates the desired shadedcrystals in the desired nanostructure.

In step 950, the structure or structures created in steps 930 and 940are tested to confirm that they properly implemented the logicidentified in step 900. This testing may be performed by any means knownin the art, such as by submitting input signals to the logic circuit andverifying that resulting output signals properly implement the logicidentified in step 900.

In some cases, this testing may be performed in a more granular manner,by providing input to and identifying output of individual gates orsubsystems of the logic circuit. Depending on the fabrication technologyused, this more granular testing may need to be performed prior to thefinal assembly of step 940.

Testing may be performed by use of any known type of test signal used tovalidate photonic signals, such as a light signal generated by anoptical laser or by an ultraviolet light.

What is claimed is:
 1. A media-defined optical logic circuit capable ofperforming a logical operation, the circuit comprising: a set ofpolyhedral prisms physically arranged such that at least one surface ofeach prism of the set of polyhedral prisms is adjacent to a distinctsurface of another prism of the set of polyhedral prisms, where a firstprism of the set of polyhedral prisms comprises a first embedded quantumdot of a set of quantum dots, a first prism-input surface, and a firstprism-output surface, such that a sufficiently energetic first photonicsignal received through the first prism-input surface is capable ofexciting the quantum dot to produce light capable of being emittedthrough the first prism-output surface as a second photonic signal,where the first prism-output surface is adjacent to a second prism-inputsurface of a second prism of the set of polyhedral prisms, such thatlight is capable of passing from the first prism to the second prismalong a path between the first prism-output surface and the secondprism-input surface, where the logic circuit is configured to respond toa set of photonic circuit-input signals, received from external lightsources, by emitting a set of photonic circuit-output signals, where theset of photonic circuit-output signals represents a binary value derivedby performing the logical operation upon a binary value represented bythe set of photonic circuit-input signals, where the arrangement of theset of polyhedral prisms allows the circuit to receive the set ofphotonic circuit-input signals through input surfaces of one or morecircuit-input prisms of the set of polyhedral prisms, and where thearrangement of the set of polyhedral prisms allows the circuit to emitthe set of circuit-output signals through circuit-output surfaces of oneor more circuit-output prisms of the set of polyhedral prisms.
 2. Thecircuit of claim 1, where one or more surfaces of the first prism arecompletely or partially shaded, and where a completely shaded surface iscapable of completely blocking a photonic signal and a partially shadedsurface is capable of attenuating a photonic signal to a degreeproportional to the degree of partial shading.
 3. The circuit of claim2, where the set of polyhedral prisms is arranged such that shadedsurfaces of the set of polyhedral prisms form a light guide that definesone or more paths through which light can travel through the set ofpolyhedral prisms, and where the light guide is capable of routingphotonic signals so as to implement an element of the binary logicoperation.
 4. The circuit of claim 1, where a first photonic signalrepresents a bit of a binary data, and where an intensity of the firstphotonic signal determines a state of the bit of binary data.
 5. Thecircuit of claim 1, further comprising: a first light-activated switch,sandwiched between two adjacent surfaces respectively comprised by twoprisms of the set of polyhedral prisms, that is capable of responding toa photonic switching signal by blocking a photonic data signal passingbetween the two prisms.
 6. The circuit of claim 5, where the firstswitch is configured to perform a logical NOT operation upon thephotonic data signal.
 7. The circuit of claim 1, where an intensity oflight emitted by an excited quantum dot of the set of quantum dots isdetermined by one or more physical characteristics of the excitedquantum dot.
 8. A method of forming an optical logic circuit, the methodcomprising: physically arranging a set of polyhedral prisms such that atleast one surface of each prism of the set of polyhedral prisms isadjacent to a surface of another prism of the set of polyhedral prisms,where a first prism of the set of polyhedral prisms comprises a firstembedded quantum dot of a set of quantum dots, a first prism-inputsurface, and a first prism-output surface, such that a sufficientlyenergetic first photonic signal received through the first prism-inputsurface is capable of exciting the quantum dot to produce light capableof being emitted through the first prism-output surface as a secondphotonic signal, and where the first prism-output surface is adjacent toa second prism-input surface of a second prism of the set of polyhedralprisms, such that light is capable of passing from the first prism tothe second prism along a path between the first prism-output surface andthe second prism-input surface; and configuring the logic circuit torespond to a set of photonic circuit-input signals, received fromexternal light sources, by emitting a set of photonic circuit-outputsignals, where the set of photonic circuit-output signals represents abinary value derived by performing a logical operation upon a binaryvalue represented by the set of photonic circuit-input signals, wherethe arrangement of the set of polyhedral prisms allows the circuit toreceive the set of photonic circuit-input signals through input surfacesof one or more circuit-input prisms of the set of polyhedral prisms, andwhere the arrangement of the set of polyhedral prisms allows the circuitto emit the set of circuit-output signals through circuit-outputsurfaces of one or more circuit-output prisms of the set of polyhedralprisms.
 9. The method of claim 8, further comprising: completely orpartially shading one or more surfaces of the first prism, where acompletely shaded surface completely blocks a photonic signal and apartially shaded surface attenuates a photonic signal to a degreeproportional to the degree of partial shading.
 10. The method of claim9, where the physically arranging further comprises: arranging the setof polyhedral prisms such that shaded surfaces of the set of polyhedralprisms form a light guide that defines one or more paths through whichlight can travel through the set of polyhedral prisms, where the lightguide is capable of routing photonic signals so as to implement anelement of the binary logic operation.
 11. The method of claim 8, wherea first photonic signal represents a bit of a binary data, and where anintensity of the first photonic signal determines a state of the bit ofbinary data.
 12. The method of claim 8, further comprising: a firstlight-activated switch, sandwiched between two adjacent surfacesrespectively comprised by two prisms of the set of polyhedral prisms,that is capable of responding to a photonic switching signal by blockinga photonic data signal passing between the two prisms.
 13. The method ofclaim 12, where the first switch is configured to perform a logical NOToperation upon the photonic data signal.
 14. A method of using anoptical logic circuit, the method comprising: submitting to the opticallogic circuit, by means of external light sources, a set of photoniccircuit-input signals, where the optical logic circuit comprises a setof polyhedral prisms physically arranged such that at least one surfaceof each prism of the set of polyhedral prisms is adjacent to a surfaceof another prism of the set of polyhedral prisms, where a first prism ofthe set of polyhedral prisms comprises a first embedded quantum dot of aset of quantum dots, a first prism-input surface, and a firstprism-output surface, such that a sufficiently energetic first photonicsignal received through the first prism-input surface is capable ofexciting the quantum dot to produce light capable of being emittedthrough the first prism-output surface as a second photonic signal, andwhere the first prism-output surface is adjacent to a second prism-inputsurface of a second prism of the set of polyhedral prisms, such thatlight is capable of passing from the first prism to the second prismalong a path between the first prism-output surface and the secondprism-input surface, where the logic circuit is configured to respond tothe set of photonic circuit-input signals by emitting a set of photoniccircuit-output signals that represents a binary value derived byperforming a logical operation upon a binary value represented by theset of photonic circuit-input signals, where the arrangement of the setof polyhedral prisms allows the circuit to receive the set of photoniccircuit-input signals through input surfaces of one or morecircuit-input prisms of the set of polyhedral prisms, and where thearrangement of the set of polyhedral prisms allows the circuit to emitthe set of circuit-output signals through circuit-output surfaces of oneor more circuit-output prisms of the set of polyhedral prisms; andreading the set of circuit-output signals emitted by the optical logiccircuit in response to receiving the photonic circuit-input signals. 15.The method of claim 14, further comprising: completely or partiallyshading one or more surfaces of the first prism, where a completelyshaded surface completely blocks a photonic signal and a partiallyshaded surface attenuates a photonic signal to a degree proportional tothe degree of partial shading.
 16. The method of claim 15, where thephysically arranging further comprises: arranging the set of polyhedralprisms such that shaded surfaces of the set of polyhedral prisms form alight guide that defines one or more paths through which light cantravel through the set of polyhedral prisms, where the light guide iscapable of routing photonic signals so as to implement an element of thebinary logic operation.
 17. The method of claim 14, where a firstphotonic signal represents a bit of a binary data, and where anintensity of the first photonic signal determines a state of the bit ofbinary data.
 18. The method of claim 14, further comprising: a firstlight-activated switch, sandwiched between two adjacent surfacesrespectively comprised by two prisms of the set of polyhedral prisms,that is capable of responding to a photonic switching signal by blockinga photonic data signal passing between the two prisms.
 19. The method ofclaim 18, where the first switch is configured to perform a logical NOToperation upon the photonic data signal.
 20. The method of claim 14,where an intensity of light emitted by an excited quantum dot of the setof quantum dots is determined by one or more physical characteristics ofthe excited quantum dot, and where the one or more physicalcharacteristics of the excited quantum dot are selected from the groupconsisting of: a physical dimension of the excited quantum dot, amaterial of composition of the excited quantum dot, and a shape of theexcited quantum dot.